This research describes modern phytolith records and distributions from subalpine surface soils in the Dalaoling Forest Reserve, and reveals its implications for local climate conditions with respect to the altitude g...This research describes modern phytolith records and distributions from subalpine surface soils in the Dalaoling Forest Reserve, and reveals its implications for local climate conditions with respect to the altitude gradient. Well-preserved phytolith morpho-types, assem- blages, and climatic indices were used to study the relationship between local vegetation and climate condi- tions. The phytolith classification system is mainly based on the characteristics of detailed morpho-types described for anatomical terms, which are divided into seven groups： long cells, short cells, bulliform cells, hair cells, pterido- phyte type, broad-leaved type, and gymnosperm type. Phytoliths originating from the Poaceae are composed of Pooideae （rondel and trapeziform）, Panicoideae （bilobate, cross, and polylobate）, Chloridoideae （short/square sad- dle）, and Bambusoideae （oblong concave saddle）. Based on the altitudinal distribution of the phytolith assemblages and the indices of aridity （Iph）, climate （Ic）, and tree cover density （D/P）, five phytolith assemblage zones have revealed the five types of climatic conditions ranging from 1,169 m to 2,005 m in turn： warm-wet, warm-xeric to warm-mesic, warm- xeric to cool-mesic, cool-xeric, and cool-mesic to cool-xeric. The Bambusoideae, Panicoideae, and Chloridoideae are the dominant vegetation at the lower-middle of the mountains, while Pooideae is mainly distributed in the higher mountains. The close relationship between phytolith assembleages and changes of altitude gradient suggest that vegetation distribution patterns and plant ecology in the Dalaoling mountains are controlled by temperature and humidity conditions. Our results highlight the importance ofphytolith records as reliable ecoclimatic indicators for vegetation ecology in subtropical regions.展开更多
文摘This research describes modern phytolith records and distributions from subalpine surface soils in the Dalaoling Forest Reserve, and reveals its implications for local climate conditions with respect to the altitude gradient. Well-preserved phytolith morpho-types, assem- blages, and climatic indices were used to study the relationship between local vegetation and climate condi- tions. The phytolith classification system is mainly based on the characteristics of detailed morpho-types described for anatomical terms, which are divided into seven groups： long cells, short cells, bulliform cells, hair cells, pterido- phyte type, broad-leaved type, and gymnosperm type. Phytoliths originating from the Poaceae are composed of Pooideae （rondel and trapeziform）, Panicoideae （bilobate, cross, and polylobate）, Chloridoideae （short/square sad- dle）, and Bambusoideae （oblong concave saddle）. Based on the altitudinal distribution of the phytolith assemblages and the indices of aridity （Iph）, climate （Ic）, and tree cover density （D/P）, five phytolith assemblage zones have revealed the five types of climatic conditions ranging from 1,169 m to 2,005 m in turn： warm-wet, warm-xeric to warm-mesic, warm- xeric to cool-mesic, cool-xeric, and cool-mesic to cool-xeric. The Bambusoideae, Panicoideae, and Chloridoideae are the dominant vegetation at the lower-middle of the mountains, while Pooideae is mainly distributed in the higher mountains. The close relationship between phytolith assembleages and changes of altitude gradient suggest that vegetation distribution patterns and plant ecology in the Dalaoling mountains are controlled by temperature and humidity conditions. Our results highlight the importance ofphytolith records as reliable ecoclimatic indicators for vegetation ecology in subtropical regions.
